Base MongoDB (Advanced)

MongoDB BasicsStage One, understanding MongoDB1, the basic form of data of MongoDB organization

MongoDB ———— Database ———— "collection ————" documentation

MySQL: Table: Rows and Columns: Fields

Application scenarios: such as real-time information about the delivery rider, logs, game character attributes, nearby people information

Application features: Real-time change of QPS

Data type: Each document is stored as a key-value pair

2. Enter and exit the database

Entry: MONGO

Exit: Exit

Stage II, library, set operation

1. Show all libraries: Shou DBS

2. Switch database: Use database name

3. View your library: DB

4. Delete library: Db.dropdatabase ()

5. View the collection inside the current library: Show collections

6. Create a collection: db.createcollection (' student ')

7. Delete collection: Db. Collection name. Drop ()

Phase III, data deletion and modification of the operation1. Inserting Data

Db. Collection name. Insert (document)

Each piece of data is a document, which is a JSON

When inserting a document, MongoDB assigns a unique objectid to the document if the _ID parameter is not specified

#example: Inserting aDb.student.insert ({name: ' Shiwei', age:18})#Add ID when insertingDb.student.insert ({_id:10,name: ' Shiwei', age:18})?#insert more than one:Db.student.insert ([{name: ' Shiwei', Sex:'Male', age:18},{Name:'Zhang San', Sex: ' Female', age:30},{Name:'John Doe', Sex: ' Male', age:48},])

2. Query Data

Db. Collection name. Find ()

#Search All: Db.student.find ()#query all, format is indented: Db.student.find (). Pretty ()#Query by criteria:> Db.student.find ({name:'zcm'}){ "_id": ObjectId ("5b3789beccd791f53ba27b05"),"name":"zcm"," Age": 22 }{ "_id": ObjectId ("5b378bc6ccd791f53ba27b07"),"name":"zcm"," Age": 22 }?> Db.student.find ({name:'zcm'},{age:1}){ "_id": ObjectId ("5b3789beccd791f53ba27b05")," Age": 22 }{ "_id": ObjectId ("5b378bc6ccd791f53ba27b07")," Age": 22 }?> Db.student.find ({name:'zcm'},{age:0}) {"_id": ObjectId ("5b3789beccd791f53ba27b05"),"name":"zcm" }{ "_id": ObjectId ("5b378bc6ccd791f53ba27b07"),"name":"zcm"}

3. Update Data

Update data

Db. Collection name. Update (

<query>, (conditions)

<update>,

{multi: <boolean>}

? )

# Full document Update: db.stu.update ({name: ' Shiwei '},{xx: ' yy '})? # specifies that the property update, through the operator $set, has the same property, only changes one data db.student.update ({name: 'zcm'},{$set: {Age :)? # Update multiple: {multi:ture}   . (If only field updates are specified)db.student.update ({name:'zcm'},{$set: {age:5}},{multi:true})

4. Delete Data

Db. Collection name. Remove (

? <query>, (conditions)

<justOne>

? )

# just delete a piece of data db.student.remove ({xx:'yy'},{justone:true})? # Delete all data that satisfies the condition:db.student.remove ({name:'zcm'})

stage four, python operation MongoDB1. Connector (drive)

Install Python package: Pip install Pymongo

Introducing Package Pymongo:import Pymongo

Establish the connection and create the client: client= Pymongo. Mongoclient (' 127.0.0.1 ', 27017)

Specify database: db=client[database name]

Specified collection: stu=db [collection name]

2. Main methods

Insert_one

Insert_many

Update_One

Update_many

Delete_one

Delete_many

Find_one

Find

3. Example

ImportPymongo?#Establish a connectionClient = Pymongo. Mongoclient ('127.0.0.1', 27017)?#get the database to manipulatedb = client['Student']?#gets the collection to manipulateCol = db['Student']?data=Col.find ()Print(data)#an object was printed to prove the connection was successful.?#Insert a piece of data#col.insert_one ({' name ': ' zcm ', ' Age ': $})?#inserting more than one data#Li = [#{' Nane ': ' Zhangsan ', ' age ': +, ' sex ': ' Nan '},#{' Nane ': ' Baby ', ' age ':, ' sex ': ' NV '},#{' Nane ': ' Dengchao ', ' age ': +, ' sex ': ' Nan '}# ]#Col.insert_many (LI)?#update One piece of data#col.update_one ({' name ': ' zcm '}, {' $set ': {' Age ': 3}})?#update more than one data#col.update_many ({' name ': ' zcm '},{' $set ': {' age ': +}})?#querying a single piece of data#find = Col.find_one ()#print (Find)?#querying multiple data returns only objects#find_d = Col.find ()#print (find_d)?#Delete a piece of data#col.delete_one ({' name ': ' zcm '},{' justone ': ' true '})?#Delete more than one piece of data#col.delete_many ({' name ': ' zcm '})

Base MongoDB (Advanced)